Two-cycle engine



April 26, 1938. R. H. SCHNEIDER 2,115,180

TWO-CYCLE ENGINE Filed May 22, 1934 2 Sheets-Sheet 1 ATTORNEYS Wggwaon Ir April 2 1938. i R. H. SCHNEIDER v 2,115,180

TW OCYCLE ENGINE Filed May 22, 1934 2 Sheets-Sheet 2 a INVEQJER BY I 9%a j ATTORNEYS Patented'Apr. 26, 1938 I 2,115,180

UNITED STATES PATENT OFFICE TWQ-CYCLE ENGINE Rudolph H. Schneider, St.Louis, Mo., assignor to Busch- Sulzer Bros-Diesel Engine Company, St.Louis, Mo., a corporation of Missouri Application May 22, 1934, SerialNo. 726,906 16 Claims, (Cl. 123-65) This invention is an improved modeof conpartition walls and 5" which are provided in struction andoperation of two-cycle engines in the cylinder block or jacket structureand which, which the scavenging and exhaust are done with thecomplementary parts of the composite through piston-controlled ports inthe cylinder manifold structure below referred to, constitute 5 wallsand its object is better general efliciency ducts for conducting the airto the cylinders and 5 of such engines, obtained in part through animthe exhaust therefrom. These ducts are adproved arrangement of thescavenging and exjacent and substantially parallel and lead to the haustsystems and by the mutual organization same side of the engine. of suchsystems in a way to give more effective The duct marked 6 leads from theair mani- 10 use of the scavenging air for super-charging and fold Iwhich extends alongside the row of cylin- 10 by other features andcombinations of features ders, common to all of them, and is suppliedwith which will be made apparent in the description air under pressurefrom any suitable .source. which follows, referring to an engineembodying Preferably this air source is an elongated Roots the newprinciples and shown for exempliflcatype blower mounted on the cylinderblock with tion thereof in the accompanying drawings. In its long rotors8 turning on horizontal axes paral- 15 the latter, lel to the airmanifold. The elongated dimen- Fig. 1 is an axial section through one ofthe sion, substantially coextensive with the row of cylinders of theengine on line II of Fig. 2; cylinders, enables the rotors with theircasing Fig. 2 is a section of Fig. 1 on line II-II, and walls 9 to serveas the floor or bottom of that Fig. 3 is a section of Fig. 2 on lineIII-J11. manifold, thereby economizing weight and also 20 In themulti-cylinder engine taken for illusspace since with the blower in thisposition spacetration, the cylinders l are arranged in a row, does nothave to be provided for it elsewhere in water-jacketed as usual andprovided with inthe engine room and by reason of its 'narrownessdividual cylinder heads containing the fuel inthe width of the engine isnot unduly extended jection valves centrally thereof. The pistons 2, aswill be apparent. Such a blower can be prac- 5 near the ends of theiroutward strokes, uncover tically operated to supply air at a rateconsiderthe zones of exhaust ports 3 and scavenging air ably in excessof the stroke volume of the engine ports 4, formed in the cylinder wallsas usual in per engine revolution and at a pressure approthis type ofengine, but instead of being respecpriate for supercharging as well asscavenging.

tively on opposite sides of the engine, as cus- The top of the airmanifold is formed by the 30 tomary,-the zones are arranged in what maybe bottom wall of the exhaust manifold i2 and its termed a fore and aftrelation, that is to say, 7 sides are closed in by the cylinder blockwall on each zone of air ports is on one side of a vertical the one handand a removable side plate 1* on plane transverse to the crankshaftthrough the the other.

axis of its cylinder, and the zone of exhaust ports The air supplied bythe blower is passed up- 35 is on the other side of that plane and, asshown wardly from this manifold through check-valves and preferred, therespective zones are on homoll0 secured to the bottom of the exhaustmaniogous sides of the cylinders. fold and through the upwardly inclinedsections The exhaust ports 3 are indicated as of the of the ducts 6which are formed in the exhaust same height as the scavenging ports, sothat both structure as indicated and which register with 40 are coveredand uncovered simultaneously by the the other sections of the ducts 6formed in the piston. but the porting may be according to any block.Since these ducts are directly subject to preferred arrangement.Preferably the air ports the exhaust heat, it will be appreciated thatthe are all in one horizontal row or tier as shown and entering air isaccordingly warmed and' someslanted upwardly or toward the cylinder headwhat expanded in transit to the ports. The air 45v and also they are setobliquely in the cylinder guides marked 4" are for giving a properdiswall so as to produce a whirling or rotary motion tribution of theair to the individual air ports. of the cylinder contents. The exhaustports are The check valves I0 may be of any suitable depreferably set atan angle the reverse of that of sign and are shown as of the horizontallouvre 0 the airports. so that they lie in positions which type (Fig.3'), one for each air duct. They ob-,,

conform more or less to the direction of whirling struct reverse flowfrom the cylinders but open during the scavenging period, thusfacilitating freely to pass air to the cylinders at that point outflowthrough them and to some extent assist-- in the stroke when the blowerpressure exceeds ing in the rotary motion. the cylinder pressure and aswill beunderstood.

The adjacent zones of ports are separated by The exhaust ports 3discharge through their 56 merous advantages in injection type engines,and

especially in large size engines, since it leaves the opposite sideclear for the fuel and lubricating pumps and for various adjunctiveapparatus which require more or less continual supervision or attention.

Each exhaust duct II is governed by a mechanical or timed valve l3 ofpoppet type, one for each duct.

The casings ll of these valves are within the composite manifoldstructure and more specifically within the exhaust header itself but thevalves are operated from the exterior as .by means of the cam shaft l5also carried on the manifold. The valve design and operation will beclear from the drawings. The cam shaft is geared to the engine crankshaft through appropriate gearing indicated in the present case by agear-train shown by the dotted pitch-circles I 6, which train alsoserves to drive the blower. Each exhaust valve is opened and closed byits cam in the appropriate sequence and once in each cycle andpreferably the angular relation of each cam on its shaft is made subjectto variation, so that it can be closed by its cam earlier or later asdesired. For this purpose the cam in Fig. 1 is shown connected to itsshaft by helical splines I1 and shiftable thereon by a lever l8, but anyof the known valve-timing gearing will su mce.

The function of the exhaust-valve is to terminate the outflow from theexhaust ports of its cylinder at a certain point in the period of. airadmission, that is to say, at or about themoment when the'combustionproducts have substantially departed andbefore air has begun to escapein appreciable amount, thereby allowing the rest of the air, whichenters while the pistoncontrolled air ports remain open,'to raise thepressure'within the cylinder and thus establish a supercharge therein.The extent of supercharge, obtained in this way, obviously depends onthe blower pressure and the duration of the open period of the air portsafter the closing of the exhaust valve, but by the proper adjustment orregulation of the exhaust valve a considerable supercharge is obtainableunder any condition and is subject to increase by advancing the time ofclosing up to the point where too large a body of combustion products isretained in the cylinder to permit emcient combustion of the fueltherein.

It will be apparent that this action is not dependent on-the compositemanifold construction nor on the particular port arrangement although itis best carried out with the ports and manifolds disposed as described,and similarly the composite manifold structure will afford itsadvantages indrawings, also except as required by the dependently of thefunction of the exhaust valve,

3,-A multi-cylinder engine having a row of I two-cycle cylinders formedwith piston-controlled air and exhaust ports, air and exhaust manifoldsrespectively therefor, extending both along one side of the row, theexhaust manifold being above the air manifold and an elongated. blowermounted on the engine below the air manifold and serving the same.

4. A composite manifold structure for multicylinder two-cycle engineshaving piston-con trolled air and exhaust ports, comprising a horizontal exhaust conduit, air ducts formed in the bottom wall thereof andcheck valves for said ducts secured to said wall and other wallsenclosing the checkvalved openings constitutin the air manifold for theengine.

5. A composite manifold structure for multicylinder two-cycle engineshaving piston-controlled air and exhaust ports, comprising a horizontalexhaust conduit secured to the cylinder block, a blower secured to theblock below said conduit, the space between said blower and conduitconstituting an air manifold, and air ducts formed in the wall of saidconduit for passing air from said air manifold to the air ports.

G. A multi-cylinder engine comprising a row of two-cycle cylinders eachhaving zones of piston-controlled air and exhaust ports, all of theports of one of said zones being located on the side of its cylinderthat is adjacent the next cylinder in the row and all of the ports ofthe other zone being located on the opposite side of the 7 cylinder, andair and exhaust manifolds both locatedon the same side of the row andrespectively in communication with said air and exhaust zones.

in the row and all of the ports in the other zone being located on theopposite side of the cylinder, and air and exhaust manifolds bothlocated on the same side of said row and respectively in communicationwith the air and exhaust-port zones of the several cylinders, saidmanifolds being incorporated in a composite header having a commondividing wall between them.

- 8. A multi-cylinder engine comprising a row of two-cycle cylinderseach having zones of piston controlled air and exhaust ports, all oftheports of one of said zones being located on the side of its cylinderthat is adjacent the next cylinder in the row and all of the ports ofthe other zone being located on the opposite side of the cylinder,

and a composite header secured to one side of said row containing airand exhaust manifolds respectively in communication with said air and 1exhaust zones.

9. A multi-cylinder-engine comprising a rowof its cylinder that isadjacent the next cylinder in the row and all of the ports of the otherzone being located on the opposite side of the cylinder, and a compositeheader secured to one side of said row containing air and exhaustmanifolds in communication with said air and exhaust zones, and alsocontaining valve structures controlling the communication.

10. A multi-cylinder engine comprising a row of two-cycle cylinders eachhaving zones of piston-controlled air and exhaust ports, all of theports of one of said zones being located on the side of its cylinderthat is adjacent the next cylinder in the row and all of the ports ofthe other zone being located on the opposite side of the cylinder, and aheader secured to one side of the row incorporating air and exhaustmanifolds connected respectively with said zones, said header carryingnon-return valves for the connections of the air manifold with said airport zones.

11. A multi-cylinder engine comprising a .row of two-cycle cylinderseachhaving zones of piston-controlled air and exhaust ports, all of theports of one of said zones being located on the side of its cylinderthat is adjacent the next cyl-' inder in the row and all of the ports ofthe other zone being located on the opposite side of the cylinder, and aheader structure secured to .one side of the row incorporating air andexhaust manifolds respectively in communication with said air andexhaust zones, and containing and carrying timed exhaust valves adaptedfor terminating the exhaust outflow from the exhaust zones to theexhaust manifold.

12. A multi-cylinder engine comprising a row of two-cycle cylinders eachhaving zones of piston-controlled air and exhaust ports, all of theports of one of said zones being located on the side of its cylinderthat is adjacent the next cylinder in the row and all of the ports ofthe other zone being located on the opposite side of the cylinder, airand exhaust manifolds both located on the same side of the row andrespectively in communication through separate ducts'with said air andexhaust zones, and valves contained in said manifolds governing all ofsaid ducts.

13. A multi-cylinder engine comprising a row of two-cycle cylinders eachhaving zones of piston-controlled air and exhaust; ports, all of theports in one of saidzones being located on the side of its cylinder thatis adjacent the next cylinder in the row and all of the ports in theother zone being located on the opposite side, said air ports beinginclined so as to whirl the cylinder contents and the exhaust portsbeing inclined in the reverse sense, and air and exhaust manifolds bothlocated on the same side of said row and respectively in communicationwith said air and exhaust-port zones.

14. A xnulti -cylinder engine comprising a ro of two-cycle cylinderseach having zones of piston-controlled air and exhaust ports, all of theports in one of said zones being located on the side of its cylinderthat is adjacent the next cylinder in the row and all of the ports inthe other zone being located on the opposite side of the cylinder, and aheader structure secured along manifolds for said air and exhaust-portzones respectively and incorporating a rotary blowerfor supplying air tosaid air manifold.

15. A multi-cylinder engine comprising a row of two-cycle cylinders eachhaving zones of piston-controlled air and exhaust ports, the air portsbeing individually inclined to their respective cylinder radii so as towhirl the cylinder contents about the cylinder axis and the exhaustports being reversely individually inclined to their respective radii tofacilitate that action, air and exhaust manifolds respectively incommunication with said air and exhaust port zones and respectivelyprovided with check-valved air ducts serving said.air ports andtimed-valved exhaust ducts serving said piston-controlled exhaust ports.

16. A multi-cylinder engine comprising a row of two-cycle cylinders eachhaving zones of piston-controlled air and exhaust ports, all of theports of one of said zones being. located on the side of its cylinderthat is adjacent the next cylinder in the row and all of the ports ofthe other zone being located on the opposite side of the cylinder, theair ports being individually inclined with respect to their respectiveradii to whirl the cylinder contents and the exhaust ports beingindividually inclined to their respective radii in the reverse sense.

